US1936936A - Preparation of catalytic material - Google Patents

Description

45v production of catalystmaterial Patented Nov. 28, 1933 Mayor Farthing l o g ler, solv'ay N. Y.,' assignor to i I Atmospheric NitrogenCorporatiomNew York, I N. Y., a corporation of New"York t a V NoDrawing- ApplicationApril 4,1929 7 4 f :Serial1NoLj'3 52i6Q8J r reclaims. (c1; 23-1224) y This invention relates to-the production of catalyst material. More particularly, this invention relates to a process. for the production of catalyst material having a substantially uniform l granule size and for the utilization of catalyst rines in theproduction of said catalyst material.

In the manufacture of catalysts containing ox- ,ides of metals wherein a mixture of materials containing as one ingredient one or more soluble 10 saltsin solution is heated to dry out the solvent and to decompose the salt and form the oxide, the product of the heating'and decomposing step is frequently in the form of amore or less hard, firm cake. This cake is then brokenup intopa'rticles and screened, the portion of the material" a V i With-finely divided alumina. This mixture is thn 'heated 'first to drive off the water, and finally to decompose the nitrate. When the "decomposition having a desirable substantially uniform particle size being separately recovered for use as a catalyst; ,A quantity or". the material is in the form of particles having asmallersi ae than isdesirable,

This portion t he so-c alled fines, may arnount to 40% or more of the total material in the original cake. 7 v

Ithas been proposed to utilize these fines by dissolving them for example in an acid, and em- 2 ploying the solution t s formed for the produc- 1 tion of a further quantity of the cake, which .is

then broken down and a gain screened, yielding ,more catalyst material having' thedesired particle size. -This method is unsatisfactory since'it requires the expenditure of considerable quanti-l ties of costly chemicalreagents to convert the fines, consisting dioxide material, into soluble This chemical conversion of the fines is accompanied, in actual practica by considerable losses of the chemical reagents employed and resalts.

. quires a comparatively expensive-installation of apparatus for carrying'itout. i

It is the object of this inventionto provide a process adapted for the utilization and recovery or these fihesin the form of catalyst material A satisfactory for commercial use'ina simplein-" expensive manner without necessitating Ltheir Q chemical conversion. Myinvention has for afurther object, the utilization of catalyst fines in the having a substantially .uniform g'ranule size. Asfused in this specification and in theclai'ms appended hereto,

, the term"granule sizeas applied to a material,

' refers to the size of the separate pieces or aggregates ofvvhich the material isv made up.

. I have to be'produced at' p l r jg .9 v1: "For purposes of illustration, the invention'is'de- -and15%'aIuminaQAhOsM" 5 As heretoforecarried out, these fines obtained alumina in amount equivalent to the cobalt discovered that lthese fines may be utiliaed in a simple inexpensive manner ithout necessitating their solution. 7 The utilization. Tof "'"thef fines, in acc'ordancelwith .this invention,' isff & fsseei l heity ma n: item .iiii ami sfie heated: nd ide vmp s i' a from which a further quantity of the catalyst is i that stage of the production of the catalystwherein a liquid, -and preferably' a solution of a salt of Lone or membrane catalyst 'componentsjfis present,- whereby'fag glomeration scribed in connection with the -production of a catalystcontaining oxidesofcobaltland aluminum suitable for '-tl1e" oxidation ofammonia,- as 'forexample, disclosed in- 17. 8. Pat. No} l,399,807fdated f- December 31,1921, satisfactory cobalt oxidealu'minlum oxide catalystmaterial'may-be re- "pared as follows? An aqueoussol tion of cobalt nitrate -is-mixed is completed, the Eproductis allowed toic'ooband the resultingcake is broken up and'screened to re- '75 "cover thatportion of the broken up materia1 having a particle size,'such that forexample it passes through a 6 mesh screen and remains one; 14 mesh nitrate "andof alumina employed-jare preferably "suchthat'the {product after decomposition of the v nitrate contains about-% cobalt 'oxide lCozQzl in'the production; of catalystmaterialf represented-a loss? In accordance withflmy invention the ex'aml'lle;"ground to pass amesh screen, and 1 present; as will be hereinafter described, and

nitrate such-that after decomposition of the'c'o r balt nitrate the product contains-cobalt" oxide -"and'aluminain the desired proportions;

example about- 85 parts of. cobalt oxide to' ab out -15* p'arts of alumina.- In other words',"the'con- "'stituents ofthe new material are so propor-" tioned that the catalyst material "produced has this substantiallythe 'samecomposit n as the fines utiliz edf in its production: The ixture isfthen glomerated mass and treatedas described above in connection with the preparation of the original catalystmaterial. The fines recovered from this second process may likewise be utilized forthe production of still further quantities of catalyst 'material; It has been found in the production of a cobalt oxide-aluminum oxide catalyst as describedabove, that aboutv 100 gms. of fines may be advantageously added to a'mixture of 15 gms.

alumina with a substantially saturated aqueous solution containing 187 gms. of cobalt nitrate. Further, it has been found that a quantity of fines substantially three: times thejcalculated' weight of catalyst from-new material, maybe added prior to the evaporation of the cobalt nitrate solution and decomposition of the nitrate to form .an agglomerated productwithout substantially changing the physical and catalytic characteristics of the catalyst, andlsatisfactory catalystsuhave been made in which the ratio of fines to new material, calculated as catalyst product variedfrom 75:25 to :75.

While the above processes for the production catalyst material illustrate and explain the present invention, it is evidentthat many'modi-' .fications maybe madein thepartioular processes as set forth and thattheinventionmay be em- ..-;ploy'ed forthe production of other catalysts or for the' utilizationof other types offinely divided catalyst material,

For example my invention is .applicableto a cobaltoxide catalyst which does not contain alumina asa promoter, by adding to the aqueous solutionof cobalt nitrate the solid Q finely divided cobalt oxide-fines resulting from .mixture to dry it and tow decompose the cobalt prior catalyst production and then heating the nitrate to form cobaltoxide. The resulting cake 2 :is broken up, nd theportion havingfor example," a'particlesize of 6 to limeshrecovered. These fines are preferably ground to pass a 100 vmesh screen and are employed in the production of a furtherquantity of the catalyst in the manner described.

iAgain, during the conversion of ammonia into nitrogen oxides by catalysis employing the above Igdescribed catalysts, some of the catalyst material maydeteriorate or disintegrate. material is available for-use as the fines in -the above de-. scribed :processesv for the production of ;new

Furthermore instead of em e wployingv a-solution of a nitrate, other liquid ag ,g-lomerating' agent "may beemployed; 1 In the first :e'xample: described above, the component of .the

' xc'atalyst other: than the cobalt oxide (the ealu- ..-mina), is mixed withthe cobalt nitrate solutionc'atalyst material.

' sandfines inthe form'of the oxide. 7 It is evil dent, however; that. this step. of theprocessmay flbeymodified by'employing a salt of aluminum which. is decomposed by -the subsequent treatmentto form aluminum oxide, and when in the claims the termcomponentsof said catalyst materia is employed, itis intended to refer to the ,components either as such, on in the form of {compounds which yield the catalyst component itself during subsequent treatment g- J V lclaim: r; ..'-V 1 .;In the 1 process of producing an ammonia goxidation-f catalyst wherein a material comprising asolution of. cobalt nitrate and. alumina is' heated for removal of 'liquid'therefrom and formation of an agglomerated mass, and the massis "broken up to .form granules of a desiredsi ze and: a substantial amount of fines, that improvement .-which comprises incorporating catalyst fines in the olid phases with a quantity of the said'nia aforesaid material.

to form granules of a desired size and a substantial amountfo'f fines, that improvement which comprises .comminuting the fines so produced to a granule size smaller than about 100 mesh,

'and incorporating said comminuted fines in the solid phase with a quantity of the said material and employing the mixture comprising the said catalyst fines in the solidphase for the production of a subsequent quantity of said catalyst by treating the mixture in the manner described for the production of agranular-catalyst fromthe.

" '3. In the process of producing an ammoniaoxidation catalyst wherein a material comprising a solution of a cobalt salt is heated for removal of liquid therefrom and formation ofan agglomerated mass, and the mass isbrokenup to form granules of a desired size and a substanfos tial amount of fines, that improvement which comprises comminuting the fines so produced to a granule size smaller than about 100 mesh and incorporating said comminuted fines in'the solid phase with a quantity of the said: material and 1 10 employing the mixture comprising the said oatalyst fines in the-solid phase for the production of a subsequent quantity of said catalyst by treating the mixture inithe manner described for the production of a 'granularcatalyst from the afore:. 1 15 said material.

4. In the process of producing an ammonia oxidation catalyst wherein a material comprising a solution of cob'altnitrate and alumina is r heated for removal ofliquid therefrom and 'forizo mation of" an agglomerated mass, and the mass is broken 'up to form granules of a desired size land a substantial amount of fines, that improvement which comprises comminuting the I fines so produced to a'granule sizesmaller than 1 z5 about 100 mesh and incorporating said comminuted fines in, the solid phase with a quantity of the said material and employingthe mixture. comprising the said catalyst fines in the solid phase for the production of a subsequent quail- 3230 tity of saidv catalyst, by treating'the mixture in the manner described for the production of a granular catalyst from the aforesaid material.

5. The processof producing a catalyst material of a substantially uniform granule size containingi35 7 an oxide of a metal which comprises mixing finely divided catalyst material in the solid phaseand containing an oxide of said metal with a predetermined quantity of a solution of a salt of the metal, heating the product to a temperature at' which the salt is decomposed-formingan oxide of the metal and an agglomerated product is ob- 'tained, maintaining said finely divided catalyst,

material in the solidphase during the aforesaid treatment andheating'reducing-the granule size of the agglomerated product; separately recovering the material'of a sub'stantially uniform "granule size andthe fines, and utilizing said fines .in the production of a further quantity of .theaforesaid catalyst: material by the process above'del50 10. Theprocess of producing a catalyst'which,

scribed as the finely divided materialmixed with comprises heating a material comprising coma salt solution in the first step.

6. In the process of producing an ammonia oxidation catalyst containing cobalt oxide that improvement which comprises mixing a quantity of said catalyst in the solid phase and in a finely divided condition with an aqueous solution of cobalt nitrate and heating the product comprising said finely divided catalyst in the solid phase to a temperature at which the salt is decomposed and an agglomerated cobalt oxide material is formed therefrom.

7. The process of producing an ammonia oxidation catalyst of a substantially uniform granule size containing an oxide of cobalt and alumina which comprises mixing a quantity of said catalyst material in the solid phase and in a finely divided condition with a predeterminedquantity of an aqueous solution of a cobalt salt and an equivalent quantity of alumina, heating the mixture comprising said finely divided catalyst in the solid phase to a temperature at'which the, salt is decomposed forming an oxideof the metal and an agglomerated product is obtained, reducing the granule size of the agglomerated product, separately recovering the material of a substantially uniform granule size and the fines, and utilizing the fines in the production of 'a further quantity of catalyst material by the process above outlined as the finely divided material treated with a salt solution in the first step.

8. In the process of producing an ammonia oxidation catalyst wherein a material comprising a' promoter and a solution of a cobalt salt is heated for removal of liquid therefrom and formation of an agglomerated mass, and the mass is broken up to form granules of a desired size and 'a'substantial amount of fines, that improvement which comprises comminuting the fines so produced-to a granule size smaller than about mesh and incorporating said comminuted fines in the solid phase with a quantity of the said material and employing the mixture comprising said fines in 3 the solid phase for the production of a subsea quent quantity of said catalyst by treating the mixture in the manner described for the produce" tion of a granular catalyst from the aforesaid material. a I r I 9. In the process of producing a granularammonia oxidation catalyst containing cobalt oxide and a promoter, that improvement which comprises mixing a quantity of said catalyst in the solid phase and in a finely divided condition and of said promoter with an aqueous solution of cobalt nitrate and heating the product comprising said finely divided catalyst in the vsolid phase to a temperature at which the salt is decomposed and an agglomerated cobalt oxide material is;

formed therefrom.

ponents of said catalyst, at least one of which is present in the material as a solutionof 'a salt,- .to remove liquid therefrom and to form an agsaid catalyst fines in the solid phase with a quantity of the aforesaid material comprising catalyst components and recovering from the mixture thus prepared catalyst granules of desired size by treating the mixture in the manner described for treating the aforesaid material. 1

11. The process of producinga cobalt oxidealuminum oxide catalyst which comprises heat- I ing a material comprising components of said catalyst, at least one of which is present in the material as a solution of thesalt, to remove liquid therefrom-and to form an agglomerated mass, breaking upthe'agglomerated mass into granules, separatingthe granules'of desired sizefrom the catalyst fines, incorporating said catalyst fines in the solidphase with a quantity of the aforesaid material comprising catalyst components and recovering from the mixture thus prepared catalyst granules of desired size'by treating the mixture in the manner'desoribed for a v treating the aforesaid material. 7

12. The process of producing an ammonia oxidation catalyst which comprises heating a material comprising a solution ofa cobaltsalt for the removal of liquidtherefrom and formation v of an agglomerated mass, breaking up the agglomerated mass, into granules, separating the granules of desiredsize from the catalyst fines, incorporating said catalyst fines in the solid phase with a quantity of the aforesaid material comprising a solution of a cobalt salt and recovering from the mixture thus prepared catalyst granules of desired size by treating the mixture in the manner described for treating the aforesaid ma: terial.

13. The process dation catalyst which comprises heating a maof producing an ammonia oxi-- I terial'comprising a solution of cobalt nitrate. to

remove liquid therefrom and to form anagglomerated mass, breaking up the agglomerated mass into granules, separating the granules of desired 'size from the catalyst fines, incorporating said catalyst fines in the solid phase with a quantity of the aforesaid material comprising cobaltnitrate'and recovering .from thejmixture thus preparedcatalyst granules of desired size by treating the mixture in the manner described for treating the aforesaid material.

; MAYOR, FART ING FOGLER.

CERTIFICATE OF CORRECTION Patent No. 1,936,936. November 28, 1933.

MAYOR F ARTHING F OGLER.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 75, claim 1, for "phases" read phase; and line 84, claim 2, for "pressed" read present;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 9th day of January, A. D. 1934,

F. M. Hopkins (Seal) Acting Commissioner of Patents.